As many as 30 relatives of African-Australians have allegedly been detained in Ethiopia following a Melbourne protest in June.
There are calls for the Australian government to help negotiate their release.
In June, sections of Melbourne's Oromo community protested against a visit by a key member of Ethiopia's ruling party, Abdi Mohamoud Omar.
The international human rights organisation Human Rights Watch alleges he had committed human rights abuses.
"Family friends would call us and say, 'Your family got locked up. Why you guys protest?'"
But pro-government supporters photographed the rally, and protesters, who requested anonymity, say the consequences were swiftly felt in their homeland.
"I found out the next day all our family were arrested. Family friends would call us and say, 'Your family got locked up. Why you guys protest?'"
Human Rights Watch's Elaine Pearson says, initially, there were reports of 30 arrests of relatives from the Melbourne protest.
She says some have subsequently been released, but others remain unaccounted for.
"We're concerned that, now, it's four months later, and, still, some of those relatives remain in detention and pretty much incommunicado."
Sinke Wesho, from Melbourne's Oromo community, says jailings emanating from the Melbourne rally could deter many from advocating on behalf of loved ones in need.
"My family, most (of) the men are in prison back home. I feel responsible that I need to respond to their cries, but I can't do much."
The head of Melbourne's independent African Think Tank, Dr Berhan Ahmed, says the Ethiopian leadership in Australia should take a stand.
"To say, 'Yes, this is a crisis that we need to deal with, and we are putting together a strategy to deal with it. And every person has a right to protest and address issues of their concern."
A spokesman for the Ethiopian government has flatly denied the allegations.
He has told SBS: "Nobody has been detained in Ethiopia because of his or her relative's participation in Australia, and the person who gave you such information was trying to mislead you."
Human Rights Watch has questioned how Abdi Mohamoud Omar was ever issued a visa to visit Australia.
The Federal Government says all non-citizens wishing to enter Australia are assessed against relevant public-interest criteria, including foreign-policy and national-security interests.
It says that includes what it calls foreign officials with potential character concerns or subject to allegations of human rights abuses.
Human Rights Watch is urging the Australian government to negotiate the immediate release of anybody detained as a result of the Melbourne rally.
